2.2 Echolocation recording
The survey was conducted in July-September 2022 and April 2023 in Komul,
including Ivirghul District (YZQ), Barkol Kazakh Autonomous County (BLK)
and Arturk County (YW). The bat surveys were conducted in two broad
ways, active recording and passive recording. Active recording — a
method of recording echolocation calls whereby the researcher actively
orients the bat detector to follow bats as long as possible in real
time; this method generally results in higher quality pulses and longer
call sequences than passive recording. Passive recording – bat
echolocation sampling from a spatially fixed recorder, in contrast to
active recording. Our survey was conducted using both methods
simultaneously. Firstly, we conducted treks in different habitats
(urban, farmland, lakes, etc.), and when bats were encountered,
echolocations were recorded using a Song Meter SM4 bioacoustic recorder
(supporting sampling rates of 8000 ~ 96000 Hz). The
microphone was tied to a stick about 5 m away and headphones could be
connected to monitor the real-time audio while recording, getting as
close as possible to the bat to record its sound waves. The next step is
to place the Song Meter SM4 bioacoustic recorder in the area where the
bats are likely to be found according to their habits, set its GPS and
the time to start and end recording (based on sunrise and sunset times),
and place the microphone as high as possible to ensure the quality of
the recorded sound waves.